1. Field of the Invention
The present invention relates in general to computers, and more particularly to a system and method for initializing a fibre channel link in a storage area network.
2. Description of the Prior Art
In today's society, computer systems are commonplace. Computer systems may be found in the workplace, at home, or at school. Computer systems may include data storage systems, or disk storage systems, to process and store data. A storage system may include various storage components, such as one or more disk drives configured in a storage environment. For example, the storage environment may include a number of disk drives implemented in an array, such as a Redundant Array of Independent Disks (RAID) topology, to provide data security in the event of a hardware or software failure. The storage environment may also include other storage components, such as controllers and interfaces to mange the flow of data.
Various components in computer systems, such as storage components, may be connected together using a fibre channel protocol, a gigabit speed data transfer technology used in a variety of settings including storage systems. When two fibre channel ports are connected to each other via a fibre channel cable, a link initialization process must complete before the two ports can exchange meaningful data. Part of this link initialization process involves determining the speed at which the link will operate. In most cases, the fibre channel ports can support multiple speeds (e.g., 1 Gb/sec, 2 Gb/sec, 4 Gb/sec) and are normally configured to execute a standard speed negotiation algorithm in order to determine, and thereby operate at, the highest common speed supported by each port. This negotiation algorithm is part of the overall fibre channel standards set by the T11 Technical Committee of the InterNational Committee for Information Technology Standards (INCITS) and the American National Standards Institute (ANSI).
While the standardized speed negotiation algorithm typically results in an optimum connection, there are occasions where the algorithm cannot be completed successfully. A failure can occur for various reasons, such as timing issues caused by large link latencies, noise on the link, or incompatible implementations of the speed negotiation algorithm. A contingency in the event of a failure is not found in the fibre channel standards.